Introducing the C++ Lambda Runtime

This post is courtesy of Marco Magdy, AWS Software Development Engineer – AWS SDKs and Tools

Today, AWS Lambda announced the availability of the Runtime API. The Runtime API allows you to write your Lambda functions in any language, provided that you bundle it with your application artifact or as a Lambda layer that your application uses.

As an example of using this API and based on the customer demand, AWS is releasing a reference implementation of a C++ runtime for Lambda. This C++ runtime brings the simplicity and expressiveness of interpreted languages while maintaining the superiority of C++ performance and low memory footprint. These are benefits that align well with the event-driven, function-based, development model of Lambda applications.

Hello World

Start by writing a Hello World Lambda function in C++ using this runtime.

This Lambda function expects an input payload to contain an S3 bucket and S3 key. It then downloads that resource from S3, encodes it as base64, and sends it back as the response of the Lambda function. This can be useful to display an image in a webpage, for example.

You can use an online base64 image decoder and paste the contents of the output file to verify that everything is working. In a real-world scenario, you would inject the output of this Lambda function in an HTML img tag, for example.

Conclusion

With the new Lambda Runtime API, a new door of possibilities is open. This C++ runtime enables you to do more with Lambda than you ever could have before.

More in-depth details, along with examples, can be found on the GitHub repository. With it, you can start writing Lambda functions with C++ today. AWS will continue evolving the contents of this repository with additional enhancements and samples. I’m so excited to see what you build using this runtime. I appreciate feedback sent via issues in GitHub.